1. Technical Field
This invention relates to a knife apparatus and method for cutting articles from a sheet or web of material. More specifically, this invention relates to a knife having a unique configuration which can be formed in or secured to the outer surface of a rotary die cutter for cutting a plurality of articles from a sheet or web of material with zero clearance between at least portions of the outer peripheries of two adjacent articles.
2. Background
Many different kinds and types of articles are manufactured today which entail cutting or stamping out a plurality of identically shaped articles from an elongated sheet or web of material. The sheet or web of material can be a single layer or a laminate formed from two or more layers. In producing such articles, trim waste is usually present, and it is beneficial from a cost standpoint to minimize such waste. Trim waste is defined as all material which does not make up a finished article. It includes waste located adjacent to the periphery of each article as well as waste cut out from the interior of an article. Even when the trim waste is kept to a minimum, its presence can still cause problems in that it has to be separated and conveyed away from the finished articles. The trim waste also has to be handled if it is to be properly disposed of, reclaimed, or recycled.
For uniquely configured articles having at least one nonlinear edge, it is very difficult to completely do away with trim waste. However, it is possible to minimize the amount of trim waste and to design the waste to have a certain profile so that it can be easier to handle as it is separated from the finished articles.
One way to minimize trim waste is to design the cutting knife to have a profile such that the knife will simultaneously cut two adjacent articles from a sheet or web of material. By arranging two or more articles across and/or along a sheet or web of material such that two articles are joined by a common peripheral segment, a reduction in waste can be obtained.
Now, a knife has been invented having a unique configuration and which can be formed in or secured to the outer surface of a rotary die cutter for cutting a plurality of articles from a sheet or web of material with zero clearance between at least a portion of the outer peripheries of two adjacent articles.